In today's scenario, heart disease is a major type of abnormality found among people all over the world. The heart disease is a major source of mortality and mobility manifested in a wide range of symptoms. The most common symptom of the heart disease is chest pain. Chest pain can also be a common symptom in many diseases other than heart disease. It can become incurable and more fatal, if proper medical assistance is not provided to a patient. An accurate and early diagnosis of the patient's condition can result in faster medical treatment and thus reduce morbidity and mortality.
Equipment used for detecting cardiac events is known as Electrocardiogram (ECG). ECG is mostly used for monitoring electrical activity of the heart. It is considered to be non-invasive and can provide immediate results.
Existing ECG machines are cumbersome and costly due to usage of number of electrodes that are attached to the body surface of the patient; namely, six positions for chest leads, and four positions for limb leads. Six limb-lead waveforms (I, II, III, AVR, AVL, and AVF) of standard 12-lead waveforms and six chest-lead waveforms (V1, V2, V3, V4, V5, and V6) of the same are derived from electric potentials of the heart that are detected and measured by the electrodes by measuring means. Diagnosis and treatment using several electrodes is possible in a hospital, or a clinic. However, accurate diagnosis of chest pain using ECG is not feasible when the patient is at remote location ((i.e., remote from any health center).
Some of the ECG units use remote devices such as, laptop, mobile phones, and telemedicine for diagnoses but do not provide accurate methods for diagnosing heart problems at a remote location (such as at home) that can be used in a simple way and do not require extensive medical knowledge before using the device.
For example US application number 2006224071 describes a method of recording 12 lead ECG with lesser number of electrodes. In this, the electrodes are located at V2 and V5 location points and at least one electrode at a level with V5 on right anterior auxiliary line, and at least one further electrode positioned on each of the right hand side and left hand side of the body. Although requiring a reduced number of electrodes in order to monitor 12 lead ECG, this method does require at least 5 electrodes including one in a very non-conventional location.
Similarly, PCT Publication WO 2004/038942 to LEE describes a 4 wired electrode recording using a mobile phone battery to detect an ECG rhythm (but not morphology). This application, however, does not indicate which locations are used and does not teach that a full 12 lead ECG may be inferred from the recordings. The electrodes are adhesive, fixed and must be placed in the correct position in order to achieve an accurate reading. In addition, the data is first transmitted to the telephone's battery and from there to the telephone itself. Finally, the method described in the above publications requires modifications in the telephone's hardware and software.
US Application Publication number 2006025695 describes a method for deriving a 12 lead ECG using a conversion matrix that allows the use of a smaller number of electrodes to predict a 12 lead ECG. However the described device uses 5 electrodes to obtain the 12 lead ECG recording. Furthermore, the application does not describe a wireless or mobile device that could analyze 12 lead ECG accurately.
European patent number EPI 188412 to Brodnick et al describes an ECG monitor connected to a plurality of lead wires, each lead wire having a transducer capable of receiving an ECG signal from a patient, the ECG monitor having a processor to process the ECG signals from the plurality of lead wires and produce ECG data representative of cardiac condition of the patient, with a wireless communication interface coupled to receive patient ECG data from the ECG monitor and to transmit patient ECG data to a health care provider. Again the issue of mobility is not addressed by Brodnick et al. in the patent application.
German patent number DE 10048746 describes a device for the receipt and conversion of ECG-signals with three electrodes which are applied to the upper torso of the patient and which are connected via a cable to an ATD converter; however the method does not produce a 12 lead ECG which is sufficiently accurate for diagnosis.
German patent number DEI 9707681 to Erbel et al. relates to a mobile telephone comprising housing, a transmitter, at least one receiver, a call number memory and buttons located on the housing. The device is configured in such a way that at least one emergency call button is mounted on the housing. However it does not teach or suggest obtaining a specific ECG configuration.
U.S. 60/820,780 (WO/2008/015667) by Cardicell LTD and Berkner, Lior describes a device utilizing three to four electrodes which is purported to record a 12-lead ECG. Most of the description relates to use of two subunits, each with two electrodes, for a total of four electrodes.
Based on the aforementioned, a device and a corresponding method are required for obtaining at least a 12 lead electrocardiogram (ECG) by utilizing a simple and cost effective mechanism that can be utilized by any user even at remote location without requiring direct assistance in measuring electrocardiogram from a health care provider. Further, the device should be operable with ease by utilizing a reduced number of electrodes.